What you need to know is what your alternator output is and then do a little math. You need to determine how much power is available to power the ignition, lights, gauges and power any accessories - and still have excess wattage to continually re-charge your battery while you ride.
The alternator output is 24 amps @ 14V. Multiplying these two numbers gives you total wattage (power). Therefore 24x14=336 watts. Not big by standards but adequate. In comparison, most Beemers put out 550 watts~.
Your engine, gauges and lighting draws approx 90 watts. With your brights on, about 105 watts. Add an occasional turn signal and LED brake light, and add another 3 watts. Worst case scenario, your V draws 105-110 watts (+/- 2%) when riding at a high enough rpm (3,000+) to produce the max alternator output of 14V. Remember, at idle and slow speeds you're not producing power. You're only consuming it. Your battery requires an additional 50 watts to keep it at peak charge, so you're up to perhaps 160 watts of required power. Basically, the same power that is required to light a few 55 watt light bulbs is about what it takes to run your V. The extra output wattage from the alternator is available for accessories. You have approx 170 watts to play with so add whatever you want as long as you dont add a huge stereo amp, speakers, heated clothing for four people and a coffee maker. Just make sure you maintain your battery properly. Keep it clean, secured in place, pos/neg posts clean and replace it every 5 years if you aren't experiencing any power issues, earlier if you are. I replace mine every 4 years whether it needs it or not. Also, choose a good battery that meets OEM specs and go with a sealed maintenance-free gel type if you're willing to spend a few extra $$. Check your earth and frame grounds often. Keep them clean and tight and the likelihood of ever experiencing battery related problems are slim to none. I check my battery and all connections/grounds every 750 miles. Probably a bit of overkill, but it's cheap insurance in avoiding electrical issues when you're in the middle of Monument Valley, Utah.